The present invention relates to an air flow metering device set forth herein. EP Patent No. 54 887 describes an air metering device wherein a section of the bypass channel is formed by a tube which has an air flow rectifier mounted therein and which is inserted in the flow channel casing in such a way that the air flow rectifier ends upstream of a temperature-dependent measuring resistance mounted in the bypass channel. This configuration not only results in increased costs because the air flow rectifier is either inserted in the tube in a press-fitting arrangement or it is held in place by additional fastening elements to prevent it from falling out but also the end of the tube in the bypass channel forms an airflow-disturbing edge producing eddy currents which are detected by the resistance and result in distortion or static in the measurement signal.